Work on Oxytricha fallax: (a) analysis of the basis of coordinated reciprocal losses of parts of the oral apparatus and integration of the residues into a single apparatus; (b) genetic analysis of nuclear and chromosomal behavior at conjugation; (c) mutational analysis of processes occurring during encystment and excystment. Work on Paramecium aurelia, syngen 4: (a) continuation of construction of multiple marker stocks, tests for linkage, and building up chromosome maps; (b) continuation of studies of the morphogenetic implications of pleiotropism and interaction between genes affecting the cell membrane, the cell cortex, and cell organelles; (c) analysis of the induction, inheritance, and function of a new structure formed in the inverted region of clones posessing a large patch of inverted kineties; (d) analysis of the physiological and morphogenetic effects of inverted kineties; (3) analysis of morphogenetic interactions between key structures of the cell cortex; (f) continued study of the question of whether DNA is present in cortical organelles (e.g.) kinetosomes and trichocysts). If time and personnel permit: continued freeze storage of stocks and tests of whether the process induces genic or chromosomal mutations; continued analysis of the basis of genetic adaptation in inbreeders as compared with outbreeders.